• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11a
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• pp.317-320
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• 2005

More strict radioactive regulations are applied to Korean nuclear power plants (NPPs) since ICRP-60 recommendation for radiation protection and has been enforced since 2003. In particular. carbon-14 and tritium concentrations are significantly higher at CANDU reactors compared to PWR reactors and this increases the risk of internal radiation exposure to workers at CANDU NPPs. Thus, it is necessary to estimate the exact amount of internal radiation exposure to workers fur radiological protection at CANDU reactors. In this paper, the current dosimetry method for carbon-14 is analyzed for the establishment of internal dosimetry for carbon-14 at domestic NPPs.

• Journal of the Korean Society of Radiology
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• v.12 no.6
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• pp.707-712
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• 2018

The number of CT examinations is increasing, and radiation exposure is also increasing. repeated tests can affect the lens and thyroid. In hospitals, there is a tendency to lack interest in major long-term radiation exposure compared to the interest in increasing image information and image quality with head CT. In this study, we analyzed the improvement of image quality by proposed method to the noisy CT images. The proposed denoising method total variance optimization only for the impulsive noise candidate pixels. Experimental results show that edge information is well preserved and impulse noise can be effectively removed. and worked very well for the images according to tube voltage and rotation time. applied to the clinical setting, it can be used as the lowest exposure condition without worrying about the image quality and it will be helpful for the CT application.

• Journal of radiological science and technology
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• v.34 no.1
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• pp.59-64
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• 2011

We investigated the radiation exposure caused by DIPS, which is used to identify accurate repositioning and tumor location in pediatric cancer patients proton therapy. To compare and analyze DIPS condition, 50 pediatric cancer patients who underwent proton therapy were selected in Ilsan K cancer-specialized hospital from March 2007 to October 2009. For DIP exposure, 0.09~1.57 mGy is measured in AP and lateral directions and 23.55 mGy is measured in CSI patients. In whole brain patient, the amount of a day DIP exposure dose was 1.13 mGy. During treatment period, who exposed the biggest DIP dose are whole brain patients, 632.71 mGy is exposed. It is 1.13% of prescribed dose, represented dose is adequate because it is not exceeded 2% of recommended dose. Even though the exposed dose is not exceeded more than 2% of prescribed in DIP exposure, we should recognize the radiation damage and genetic influences to pediatric cancer patients, who is much sensitive to radiation and has longer mean residual life time. Therefore, DIPS guideline for pediatric cancer patients should be indicated to minimize the radiation exposure.

• Journal of the Korean Society of Radiology
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• v.16 no.3
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• pp.273-279
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• 2022

In order to reduce the absorbed dose given to the patient during dental radiography, a sensor that inserts a shield into the intraoralsensor was designed. Using the designed sensor, the change in absorbed dose depending on whether or not a shield was used was evaluated. The system used to evaluate the absorbed dose is VEX-S300C from Vatech, and the energy spectrum of X-rays was obtained through SPEKTR simulation based on the irradiation conditions of 65 kV, 3 mA, and 0.15 sec, and the number of photons for each energy was derived. After designing the system through Genat4 Application for Tomographic Emission(GATE) simulation, the energy spectrum obtained was used as a radiation source to calculate the absorbed dose. Lead was used for the shield, and simulations were performed at 0.1 mm thickness intervals from 0.1 mm to 0.5 mm was evaluated. In the case of using an X-ray field with a diameter of 60 mm, the decrease in absorbed dose according to the presence or absence of a shield decreased exponentially as the thickness of the shield increased. In addition, when a 20 mm × 30 mm field was used, the absorbed dose was significantly reduced even when no shield was used, and it was confirmed that the absorbed dose was further reduced when a shield was used.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.432-439
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• 2018

The purpose of this study was to analyze the knowledge, attitudes, safety management behavior, and radiation anxiety of dental hygienists and to analyze affecting factors in order to improve the level of radiation safety management and reduce anxiety. The study period consisted of 280 dental hygienists working in Jeollabuk-do from September 10 to October 31, 2017 using the SPSS 12.0 program, frequency, descriptive statistics, and multiple regression analysis. The average knowledge level of radiation quality control was 8.07, and the correct answer rate was 75.3%. The attitude level was 96.1%, and the radiation safety management behavior was 4.11 for the photographer and 4.58 for the 'always wear a TLD (personal dosimeter) during radiography'. Patient radiation safety management behavior was 3.86, and the highest was '4.69' to confirm pregnancy of the woman before radiography. Radiation-covered lining was 3.86, and was the highest at 4.13 for 'I am concerned about fetal health when I am pregnant'. Factors affecting radiation exposure anxiety were lower radiation safety management behaviors, lower age, lower radiographic experience, higher educational background, higher monthly income, and higher job title (p<0.05). Based on the above results, dental hygienists had strong knowledge, attitudes, and safety management practices for radiation quality control. However, since anxiety related to radiation exposure was high, it is possible to improve radiation safety management level and reduce radiation exposure anxiety.

• Journal of Radiation Protection and Research
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• v.28 no.3
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• pp.207-213
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• 2003

Carbon-14 is one of the major radionuclides released by CANDU Nuclear Power Plants(NPPs). It is almost always emitted as gas through the stack. From CANDU NPPs about 95% of all carbon-14 is released as carbon dioxide. Carbon-14 is a low energy beta emitter which, therefore, gives only a small skin dose from external radiation. As carbon dioxide Is physiologically rather inert gases for man's metabolism, the inhalation dose is probably less than 1 % of the ingestion dose. But this source of carbon-14, formed in a closed, nor-oxidative environment, was subsequently released into the workplace as an insoluble particulate when these systems were opened lip for re-tubing at CANDU NPPs. As a part of the improvement of dosimetry program at Wolsong Nuclear Power Plants, the carbon-14 metabolism based on references was investigated and studied to setup the internal dosimetry program due to inhalation of carbon-14.

• Journal of Radiation Protection and Research
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• v.36 no.2
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• pp.99-106
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• 2011

Tritium is the one of the most important radionuclide for workers in nuclear power plants (NPPs) and the public, from the dosimetric point of view. Humans are likely to have internal radiation exposure by tritium inhalation. Radiation exposure by tritium accounts for approximately 7% and 60~90% of the total radiation exposure of NPP workers and the public during normal operation, respectively. Thus, many researches have been conducted to estimate the internal dose by tritium precisely in the world. In terms of tritium dosimetry, this paper provides the current status of research for tritium metabolism and dosimetry.

• Journal of radiological science and technology
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• v.34 no.3
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• pp.209-214
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• 2011

Goal of this study was to measure effective radiation dose of highly exposed patients who were treated by TACE, interventional radiology from June to September 2010. The effective radiation dose was approximately measured by weighted DAP (dose area product) with the ionization chamber which is inserted in angiography equiment (Philips Allura Xper FD 20). Radiation dose was measured by TLD which was attached to patients' thyroid and genital gland. The average of ED (effective dose) was 18.43${\pm}$6.63 mSv per person and the average of radiation dose of thyroid and genital gland was 0.37 mSv, 0.77 mSv, respectively. The mean radiation dose of operators who wear the protector was 0.07 mSv for thyroid, and 0.01 mSv for genital gland, respectively. All staffs involved in TACE treatment, have to keep them aware and use the appropriate protectors to reduce the radiation dose of patient.

• Proceedings of the Korea Contents Association Conference
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• 2017.05a
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• pp.307-308
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• 2017

방사선구역내의 종사자 간의 피폭선량 비교와, 동일한 구역내에서 임상실습에 임하는 학생들의 선량을 비교하여 방사선방어의 최적화에 대한 기초자료를 제공하고자 하였다. 연구대상은 2016년 1월부터 동년 12월까지 C대학병원 방사선관리구역에 재직중인 방사선관계종사자 121명과 방사선작업종사자 36명, 그리고 8주간의 임상실습을 이수한 121명의 학생을 비교 대상으로 하였다. 방사선관계종사자와 작업종사자 간의 평균 심부 및 표층선량은 관계종사자가 각각 $.7440{\pm}1.676mSv$와 $.7753{\pm}1.730mSv$ 가장 높게 나타났으며, 통계적으로 매우 유의하였다(p<.01). 3그룹간에는 심부선량의 경우 임상실습학생이 $.143{\pm}.136mSv$로 가장 높게 나타났고, 표층선량에서도 $.1513{\pm}.139mSv$로 가장 높게 나타났으며, 작업종사자가 두 경우 모두 가장 낮았으며, 그룹간의 평균의 차이는 통계적으로 매우 유의하였다(p<.01). 결론적으로 ALARA 원칙에 의거 철저한 관리가 필요하며, 특히 방사선안전관리의 사각지대에 놓여 있는 임상실습 학생에 대한 체계적인 피폭선량 관리가 필요할 것으로 사료된다.

• Journal of radiological science and technology
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• v.35 no.2
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• pp.141-149
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• 2012

The aims of this study are to assess external radiation exposed doses of body and hands of nuclear medicine workers who handle radiation sources, and to measure radiation exposed doses of the hands induced by a whole body bone scan with high frequency and handling a radioactive sources like $^{99m}Tc$-HDP and $^{18}F$-FDG in the PET/CT examination. Skillful workers, who directly dispense and inject from radiation sources, were asked to wear a TLD on the chest and ring finger. Then, radiation exposed dose and duration exposed from daily radiation sources for each section were measured by using a pocket dosimeter for the accumulated external doses and the absorbed dose to the hands. In the survey of four medical institutions in Incheon Metropolitan City, only one of four institutions has a radiation dosimeter for local area like hands. Most of institutions uses radiation shielding devices for the purpose of protecting the body trunk, not local area. Even some institutions were revealed not to use such a shielding device. The exposed doses on the hands of nuclear medicine workers who directly handles radioactive sources were approximately twice as much as those on the body. The radiation exposure level for each section of the whole body bone scan with high frequency and that of the PET/CT examination showed that radiation doses were revealed in decreasing order of synthesis of radioactive medicine and installation to a dispensing container, dispensing, administering and transferring. Furthermore, there were statistically significant differences of radiation exposure doses of the hands before and after wearing a syringe shielder in administration of a radioactive sources. In this study, although it did not reach the permissible effective dose for nuclear medicine, the occupational workers were exposed by relatively higher dose level than the non-occupational workers. Therefore, the workers, who closely exposed to radioactive sources should be in compliance with safety management regulations, and take actions to maximally reduce locally exposed dose to hands monitoring with ring TLD.